/* using what is functional? is a header file that is part of the standard c++ library. It provides a set of pre-defined class templates for function objects. Operations include: ** arithmetic: - plus, minus, multiplies, divides, modulus, and negate. ** comparisions: - equal_to, not_equal_to, greater, less, greater_equal, and less_equal ** logic: - logical_and, logical_or, and logical_not Reference: https://en.wikipedia.org/wiki/Functional_(C%2B%2B) */ #include #include // using namespace std; // << no! // first define a template function template void printValue(T value) { std::cout << value << std::endl; } int main() { // A function wrapper to a function std::function funcA = printValue; funcA(2015); // A function wrapper to a function pointer std::function funcB = &printValue; funcB(2016); // A function wrapper to a lamda function std::function funcC = [](int value) {std::cout << value << std::endl; }; funcC(2017); // A function wrapper generated by std::bind() // * = see: http://www.cplusplus.com/reference/functional/bind/ // pass a predefined paramenter when binding std::function funcD = std::bind(printValue, "PI is"); funcD(); // A function wrapper generated by std::bind() // * = see: http://www.cplusplus.com/reference/functional/bind/ // * - see: http://www.cplusplus.com/reference/functional/placeholders/ //pass a parameter when calling the function std::function funcE = std::bind(printValue, std::placeholders::_1); funcE(3.14159); return 0; }

Using Functional